Summary: Iron deficiency or overload syndromes are a major cause of pathology in billions of humans worldwide. While thalassemia syndromes are most commonly associated with iron overload, other anemias that result in ineffective erythropoiesis (myelodysplastic syndromes, sideroblastic anemia, congenital dyserythropoietic anemia, pernicious anemia) or require frequent transfusions (sickle cell syndromes, aplastic anemia) also manifest iron overload. Iron overload may also be caused by transfusional therapy and genetic mutation. As a result, the patients develop multiple endocrine abnormalities including diabetes, liver failure, heart failure, and bone pathology. An information-based approach was taken in our laboratory to identify erythroblast proteins that may be involved in this diseases process. Among candidate molecules, the cytokine named GDF15 was studied and determined to regulate iron via inhibition of hepcidin production. Additional studies have been performed to explore other candidate molecules and determine other functions of GDF15 in human disease.